A place for a website or app to run
When someone visits a website, their browser asks a server for its pages and files. Hosting means keeping those files, or the software that creates the pages, on computers that can respond to those requests. An app may also need hosted software and a database behind it.
A team can run its own servers or use a hosting provider. The provider might rent the team a server to manage, or offer a service that handles more of the setup. A website deployment platform such as Netlify or Vercel can build a site from a repository and host the result; cloud providers offer a wider range of ways to run apps and store data.
Hosting, domains, and deployment
A domain name is the address people type, such as example.com. Hosting is where the website or app runs. DNS helps the browser find it from the domain name. A team can change its hosting without changing its domain, though it may need to update its DNS settings.
Deployment puts a version of the software into its hosting environment. A Git hosting provider such as GitHub stores the source code and supports collaboration; keeping code there does not, by itself, make the website live.